Method of making smooth castings



15 the mo ten metal may be 20 smoothness are largely reduced.

Patented Sept. 11, 1928.

UNITED, Snares PATENT on-ice.

' mum. 'r. e. sm'rn, or s'r. 'riours, l ussouar,

' IETHOD OF MAKING SMOOTH GASTINGS.

No Drawing.

This invention relates to a method of making smooth castings. In making castings by the use of molds wherein the mold walls comprise sand or [other finely divided mineral particles, the molten metal has a tendency to penetrate the walls of the molds, with the result that thesurface of the casting is rough. After the casting is removed from the mold it is neces- 10 sary to smooth the castin by machining'or other treatment resultingm increased cost of production. 7

The present invention rovides a method whereb penetration of t e moldwalls by revented so that castings ma be formed w1th comparatively smooth sur aces, with the result that the operations are iacilitated and the amount of time and cost required to obtain the desired Application med Kay 24, 1926. Serial No. 111,374.

sand or other mineral -particles.

What I claim and desire to secure by Letters Patent is 1 1. A facing composed of powdered barytes (BaSO for the-walls of molds and cores used as casting agencies. p

2. A facing for the walls of molds, and

cores used as castin agencies, composed of bargtes (BaSOJ a hering to the walls of sai cast mg agencies.

SAMUEL T. G. SMITH. 

